The argument challenges dominant approaches to education for sustainability through adopting a theoretical framework grounded in broad ontological realism but epistemological relativism, consonant with both Darwin and a fully semiotic account of living and learning (Stables & Gough, 2006; Stables, 2005, 2006). This framework draws together strands from a number of areas of academic inquiry, and is set out in an introductory section. Implications of the resulting ontological/epistemological juxtapositioning are then explored, and applied in relation to educational aspects of a number of environmental examples, most particularly climate change. In the light of this, further discussion of the relationship between the natural world and human meaning-making leads to a number of conclusions regarding the most appropriate curricular approach for environmental or sustainability education.